Sensing flow and control of liquid application using an agricultural machine with row pressure sensors

ABSTRACT

An agricultural machine applies liquid material to a field. Valve control signals control valves to apply the liquid material. Row pressure on the agricultural machine is sensed to identify when the valve is opened to apply the liquid material. A flow meter senses a flow of liquid applied to the field. The valve control signals are generated, based on the row pressure, and the sensed flow.

CROSS-REFERENCE TO RELATED APPLICATION

The present application is a divisional of and claims priority of U.S.patent application Ser. No. 16/054,182, filed Aug. 3, 2018, the contentof which is hereby incorporated by reference in its entirety.

FIELD OF THE DESCRIPTION

The present description relates to agricultural machines. Morespecifically, the present description relates to controlling liquidapplication using an agricultural machine.

BACKGROUND

There is a wide variety of different types of agricultural machines.Some agricultural machines are used to apply a liquid substance to afield. These agricultural machines can include, for instance, plantersthat have row units, sprayers, tillage equipment with sidedress bars,air seeders, etc.

A row unit is often mounted on a planter with a plurality of other rowunits. The planter is often towed by a tractor over soil where seed isplanted in the soil, using the row units. The row units on the planterfollow the ground profile by using a combination of a downforce assemblythat imparts a downforce on the row unit to push disc openers into theground and gauge wheels to set depth of penetration of the disc openers.

Row units can also be used to apply liquid material to the field overwhich they are traveling. In some scenarios, each row unit has apulse-controlled valve (such as a valve controlled using a pulse widthmodulated signal) that is coupled between a pump (that pumps liquid froma source of liquid material), and an application assembly. As the valveis pulsed, the valve is moved between an open position and a closedposition so liquid passes through the valve, from the source to theapplication assembly, and is applied to the field. Other row units mayhave valves that need not be pulse controlled.

An agricultural sprayer often includes a tank or reservoir that holds asubstance to be sprayed on an agricultural field. The sprayer includes aboom that is fitted with one or more nozzles that are used to spray thesubstance on the field. A pump pumps the substance from the reservoir,along the boom, to the nozzles. As the sprayer travels through thefield, the boom is disposed in a deployed position and the substance ispumped from the tank or reservoir, through the nozzles, so that it issprayed or applied to the field over which the sprayer is traveling. Aswith row units, the nozzles can have corresponding valves that arecontrolled by a pulsed control signal (such as a pulse width modulatedsignal). As the control signal pulses, the valve is moved between anopened position and a closed position. When in the open position, liquidpasses through the valve, so that it can be applied to the field. Othersprayers may have valves that are not operated by a pulse controlsignal.

These are just two examples of agricultural machines that can be used toapply a liquid material to a field. Others can be used as well.

The discussion above is merely provided for general backgroundinformation and is not intended to be used as an aid in determining thescope of the claimed subject matter.

SUMMARY

An agricultural machine applies liquid material to a field. Valvecontrol signals control valves to apply the liquid material. Rowpressure on the agricultural machine is sensed to identify when thevalve is opened to apply the liquid material. A flow meter senses a flowof liquid applied to the field. The valve control signals are generated,based on the row pressure, and the sensed flow.

This Summary is provided to introduce a selection of concepts in asimplified form that are further described below in the DetailedDescription. This Summary is not intended to identify key features oressential features of the claimed subject matter, nor is it intended tobe used as an aid in determining the scope of the claimed subjectmatter. The claimed subject matter is not limited to implementationsthat solve any or all disadvantages noted in the background.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a top view of one example of a planting machine.

FIG. 2 shows a side view of one example of a row unit of the plantingmachine illustrated in FIG. 1.

FIG. 3 shows a pictorial view of a self-propelled sprayer.

FIG. 4 is a block diagram of one example of a portion of the sprayershown in FIG. 3.

FIG. 5 is a block diagram of one example of a valve control system.

FIGS. 6A and 6B (collectively referred to herein as FIG. 6) show a flowdiagram illustrating one example of the operation of the valve controlsystem.

FIG. 7 is a flow diagram showing one example of the operation ofseed/chemical synchronization logic.

FIG. 8 shows an example of a machine in a remote server architecture.

FIG. 9 is a block diagram showing one example of a computing environmentthat can be used in the architectures shown in the previous FIGS.

DETAILED DESCRIPTION

The present description proceeds with respect to two different examplesof agricultural machines that apply a liquid substance to a field. Thefirst is a planter and the second is a sprayer. These are examples only,and it will be appreciated that the present discussion could just aseasily apply to other agricultural machines.

FIG. 1 is a top view of one example of an agricultural planting machine100. Machine 100 is a row crop planting machine that illustrativelyincludes a toolbar 102 that is part of a frame 104. FIG. 1 also showsthat a plurality of planting row units 106 are mounted to the toolbar102. Machine 100 can be towed behind another machine, such as a tractor.FIG. 1 shows that liquid material can be stored in a tank 107 and pumpedto valves 109 through a supply line 111. In one example, a valve controlsystem 113 controls valves 109. In one example, system 113 controlsvalves 109 using a pulse width modulated control signal, although theycan be controlled with a non-pulsed control signal as well. When theyare pulsed, the flow rate through valve 109 is based on the duty cycleof the control signal (which controls the amount of time the valves areopen and closed). The valves 109 are connected to an applicationassembly that applies liquid to the field.

FIG. 1 also shows that in one example, planter 100 includes a flow meter131 that senses flow of fluid from tank 107 through the supply line 111.Where planter 100 has a liquid return line that returns liquid to tank107 from supply line 111, then it can also have a return flow meter 135that senses the flow of liquid returned to tank 107. The differencebetween the flow sensed by flow meter 131 (exiting tank 107 into supplyline 111) and the flow sensed by meter 135 (returning to tank 107 fromsupply line 111) is indicative of the flow of liquid applied throughnozzles 109.

Planter 100 also illustratively includes a pressure sensor 133 thatsenses pressure in supply line 111. It can have multiple pressuresensors mounted to sense pressure at different locations along supplyline 111 as well. Flow meter 131 illustratively generates a boom flowsignal indicative of the fluid flow (such as mass flow rate) throughsupply line 111 and provides that signal to valve control system 113.Flow meter 135 generates a return flow signal and provides that signalto valve control system 113 as well. Pressure sensor 133 illustrativelygenerates a supply line pressure signal indicative of the pressure insupply line 111, and provides that signal to valve control system 113.Where there are multiple pressure sensors along supply line 111, theyeach generate a different supply line pressure signal and supply it tosystem 113. As is discussed in greater detail below, those signals canbe used to identify an operational characteristic of the valves 109and/or corresponding application assemblies (such as whether they areclogged or partially clogged, the flow rate through them duringoperation, the duration of the pulses, flow volume, etc.). They can alsobe used in controlling certain portions of planter 110.

FIG. 2 is a side view showing one example of a row unit 106, with valve109 and system 113 shown as well, in more detail. Row unit 106illustratively includes a chemical tank 110 and a seed storage tank 112.It also illustratively includes a disc opener 114, a set of gauge wheels116, and a set of closing wheels 118. Seeds from tank 112 are fed bygravity into a seed meter 124. The seed meter controls the rate at whichseeds are dropped into a seed tube 120 or other seed delivery system,such as a brush belt, from seed storage tank 112. The seeds can besensed by a seed sensor 122, which generates a seed signal 123indicative of a speed passing through seed tube 120. Signal 123 can beprovided to pulsing valve control system 113.

In the example shown in FIG. 2, liquid material is pumped through supplyline 111 to an inlet end of valve 109. Valve 109 is controlled bycontrol system 113 to open and close to allow the liquid to pass fromthe inlet end of valve 109 to an outlet end. System 113 can use a pulsewidth modulated signal to control the flow rate through valve 109, butthis is just one example and other control signals can be used tocontrol valves 109.

As liquid passes through valve 109, it travels through an applicationassembly 115 from a proximal end (which is attached to an outlet end ofvalve 109) to a distal tip (or application tip) 117, where the liquid isdischarged into a trench, or proximate a trench, opened by disc opener142 (as is described in more detail below).

Before describing the operation of row unit 106 and valve control system113 in more detail, a brief overview of some parts of row unit 106 andtheir operation, will first be discussed. First, it will be noted thatthere are different types of seed meters, and the one that is shown isshown for the sake of example only. For instance, in one example, eachrow unit 106 need not have its own seed meter. Instead, metering orother singulation or seed dividing techniques can be performed at acentral location, for groups of row units 106. The metering systems caninclude rotatable discs, rotatable concave or bowl-shaped devices, amongothers. The seed delivery system can be a gravity drop system (such asthat shown in FIG. 2) in which seeds are dropped through the seed tube120 and fall (via gravitational force) through the seed tube into theseed trench. Other types of seed delivery systems are assistive systems,in that they do not simply rely on gravity to move the seed from themetering system into the ground. Instead, such systems actively capturethe seeds from the seed meter and physically move the seeds from themeter to a lower opening, where they exit into the ground or trench.

A downforce actuator 126 is mounted on a coupling assembly 128 thatcouples row unit 106 to toolbar 102. Actuator 126 can be a hydraulicactuator, a pneumatic actuator, a spring-based mechanical actuator or awide variety of other actuators. In the example shown in FIG. 2, a rod130 is coupled to a parallel linkage 132 and is used to exert anadditional downforce (in the direction indicated by arrow 134) on rowunit 106. The total downforce (which includes the force indicated byarrow 134 exerted by actuator 126, plus the force due to gravity actingon row unit 106, and indicated by arrow 136) is offset by upwardlydirected forces acting on closing wheels 118 (from ground 138 andindicated by arrow 140) and double disc opener 114 (again from ground138 and indicated by arrow 142). The remaining force (the sum of theforce vectors indicated by arrows 134 and 136, minus the force indicatedby arrows 140 and 142) and the force on any other ground engagingcomponent on the row unit (not shown), is the differential forceindicated by arrow 146. The differential force may also be referred toherein as the downforce margin. The force indicated by arrow 146 acts onthe gauge wheels 116. This load can be sensed by a gauge wheel loadsensor which may be located anywhere on row unit 106 where it can sensethat load. It can also be placed where it may not sense the loaddirectly, but a characteristic indicative of that load. Both sensing theload directly or indirectly are contemplated herein and will be referredto as sensing a force characteristic indicative of that load (or force).For example, it can be disposed near a set of gauge wheel control arms(or gauge wheel arm) 148 that movably mount gauge wheels 116 to shank152 and control an offset between gauge wheels 116 and the discs indouble disc opener 114, to control planting depth. Arms (or gauge wheelarms) 148 illustratively abut against a mechanical stop (or arm contactmember-or wedge) 150. The position of mechanical stop 150 relative toshank 152 can be set by a planting depth actuator assembly 154. Controlarms 148 illustratively pivot around pivot point 156 so that, asplanting depth actuator assembly 154 actuates to change the position ofmechanical stop 150, the relative position of gauge wheels 116, relativeto the double disc opener 114, changes, to change the depth at whichseeds are planted. This is described in greater detail below.

In operation, row unit 106 travels generally in the direction indicatedby arrow 160. The double disc opener 114 opens a furrow in the soil 138,and the depth of the furrow 162 is set by planting depth actuatorassembly 154, which, itself, controls the offset between the lowestparts of gauge wheels 116 and disc opener 114. As discussed above, seedsare metered or singulated by a metering system (e.g., seed meter 124)and positioned in a furrow by the seed delivery system. Where the seeddelivery system is a gravity drop system, the seeds are dropped throughseed tube 120, into the furrow 162 and closing wheels 118 close thesoil. Where the seed delivery system is an assistive system, the seed ispositioned in, or captured by, the assistive system and moved to alocation proximate the furrow 162 where it is deposited or placed in thefurrow 162. System 113 controls valve 109 to apply a liquid throughapplication assembly 114 to the field over which row unit 106 istraveling. The liquid can be applied in, or proximate, furrow 162.

There may be seed sensors in both the seed metering system and the seeddelivery system. In another example, there may be a seed sensor only inthe seed metering system, or only in the delivery system, or elsewhere.In the example illustrated in FIG. 2, only seed sensor 122 is shown, andit is shown mounted to seed tube 120 so that it detects seeds passingthrough seed tube 120. A seed sensor on the seed metering system maysense the presence or absence of seeds in the seed metering system. Theseed sensors are illustratively coupled to their corresponding systems(the seed metering system and/or seed delivery system) to sense anoperating characteristic of the corresponding system. The sensors sensethe presence or absence of a seed, or sense a characteristic indicativeof a seed spacing interval within the system on which it is deployed.

The seed sensors can include a transmitter component and receivercomponent. The transmitter component emits electromagnetic radiation, orlight, into the seed metering system or seed delivery system through atransparent or translucent side wall of the system. The receivercomponent then detects the reflected radiation and generates a signalindicative of the presence or absence of a seed adjacent to the sensor(e.g., sensor 122) based on the reflected radiation. Of course, this isjust one example of a seed sensor, and others may be used as well. Theseed sensor signal 123, generated by the seed sensor, is provided backto valve control system 113, where it can be conditioned (such asamplified, filtered, linearized, normalized, etc.).

FIG. 2 also shows that, in one example, a pressure sensor 127 isdisposed to sense pressure in valve 109. The pressure sensor in valve109 can be a differential pressure which measures the pressure dropacross valve 109, or it can be a pressure sensor that senses thepressure on the outlet end of valve 109, but upstream of the distal tip117 of application assembly 115. That can be compared to the supply linepressure sensed by pressure sensor 133 (or where there are multiplesupply line pressure sensors the signal from the closest such sensor) toobtain the pressure drop across the valve 109. Pressure sensor 127illustratively generates a pressure sensor signal indicative of thesensed pressure, and provides that pressure sensor signal to valvecontrol system 113.

FIG. 3 is a partial pictorial, partial block diagram showing one exampleof a self propelled agricultural spraying machine (or sprayer) 180.Sprayer 180 illustratively includes an engine in engine compartment 182,an operator in operators compartment 184, a tank 186, that stores liquidmaterial to be sprayed, and an articulated boom 188. Boom 188 includesarms 190 and 192 which can articulate or pivot about points 194 and 196from a travel/storage position to a deployed position illustrated inFIG. 3. Agricultural sprayer 180 is illustratively supported formovement by a set of traction elements, such as wheels 198. The tractionelements can also be tracks, or other traction elements as well.

When a spraying operation is to take place, boom arms 190 and 192articulate outward to the position shown in FIG. 3. Boom 188 carriesnozzles 200 that spray material that is pumped from tank 106 throughboom 188 by pumping system 202, onto the field over which sprayer 180 istraveling. As with row unit 106 shown in FIG. 2, the flow of liquidmaterial through each of the nozzles 200 is controlled by acorresponding valve 204. In the example illustrated in FIG. 3, eachnozzle 200 has a corresponding valve 204. However, it will be noted thata single valve 204 may control the passage of material through multipledifferent nozzles. These and other architectures and arrangements arecontemplated herein. The valves are controlled by valve control system113.

FIG. 3 also shows that sprayer 180 illustratively includes a boom flowmeter 206 and a boom pressure sensor 208. Flow meter 206 illustrativelysenses a value indicative of the flow of liquid material from tank 186through boom 188. In one example, the value is indicative of the massflow rate of the liquid material through boom 188. FIG. 3 also showsthat pressure sensor 208 illustratively senses the pressure within boom188. Sprayer 180 can have a return line that returns liquid from boom188 to tank 186. In that case, flow meter 207 senses the return flow sothe flow of liquid applied through the nozzles 204 is the difference inflow measured or sensed by meters 206 and 207. Further, there can beadditional boom pressure sensors along boom 188. For instance, there maybe a pressure drop across boom 188 so that multiple pressure sensorsalong boom 188 capture this pressure drop. These and other arrangementsare contemplated herein.

It will be noted that the various pressure sensors described herein canbe arranged in a number of different ways. For instance, they can bearranged so that they are referenced to atmospheric pressure, or theycan be arranged as sets of pressure sensors or a differential pressuresensor, so they can be used to obtain a differential pressure indicativeof the pressure drop across the valves or across other portions of theagricultural machine that is delivering the liquid material to thefield.

FIG. 4 is a partial block diagram, partial schematic diagram showing oneexample of a portion of sprayer 180, illustrated in FIG. 3. Some of theitems illustrated in FIG. 4 are similar to those shown in FIG. 3, andthey are similarly numbered.

FIG. 4 shows that a row pressure sensor 210 is disposed relative to eachvalve 204 or nozzle 200 (or to an outlet hose where one is used) on boom188. Row pressure sensors 210 are configured so that they provide asignal indicative of the pressure drop across the valve 200 or thenozzle 204, or the valve/nozzle combination 200/204 or so that such avalue can be derived. By way of example, it may be that row pressuresensor 210 senses the pressure at the outlet end of valve 204 and theinlet end of nozzle 200. This pressure can be compared to the boompressure sensed by boom pressure sensor 208 (or, where multiple boompressure sensors are provided along boom 188, the boom pressure sensorlocated closely proximate the row pressure sensor 210 under analysis) inorder to obtain a pressure drop across valve 204. Sensor 210 can also bereferenced to atmospheric pressure in order to obtain a pressure dropacross nozzle 200. Thus, by sampling the row pressure sensor signalduring pulsed operation of valve 204, the value of the row pressure canbe used to determine whether valve 204 is operating, whether nozzle 200is clogged or partially clogged, the duration of the pulses in thepulsed operation of valve 204, the amount of liquid material that flowsthrough valve 204 and nozzle 200 during each pulse, among other things.These are all described in greater detail below. In one example, thevalves are controlled so that the liquid material flows through nozzles200 and is sprayed (as indicated by arrows 212) onto the field 214 overwhich the sprayer is traveling.

It will be noted that valve control system 113 illustratively generatescontrol signals to control valves 204. The control signals areillustratively pulsed control signals (such as pulse width modulatedsignals) where the amount of time that the valves 200 are open andclosed is determined by the duty cycle of the pulse width modulatedsignal). This is just one example and control system 113 need notcontrol valves 204 with a pulsed control signal. It will also beappreciated that valve control system 113 can be similar to, ordifferent from, valve control system 113 described above with respect toFIGS. 1 and 2. For the purposes of the present description, it will beassumed that they are similar, so that only valve control system 113,described with respect to FIGS. 1 and 2 above, will be described in moredetail.

FIG. 5 is a block diagram showing one example of valve control system113 in more detail. In the example shown in FIG. 5, valve control system113 illustratively controls the valves using a pulsed control signal, sothat some items dealing with the pulsed operation are described.However, where the control signal is not a pulsed control signal, thoseitems need not be used.

Valve control system 113 illustratively includes one or more processors300, pressure sampling logic 302, orifice identifier logic 304, rowpressure identifying logic 306, row flow rate identifier logic 308,error/time delay correction logic 310, valve control signal generator312, pulsed duration logic 314, pulse frequency logic 316, controlsignal generator logic 318, valve blockage detector 320, data store 321,flow volume detector 322, seed/chemical correlation logic 324, and itcan include other items 326. Seed/chemical correlation logic 324 caninclude seed location/pattern identifier 325, pulse frequency controller327, pulse duration controller 329 and it can include other items 331.It will also be noted that, in one example, valve control system 113 caninclude a communication system 328 and user interface logic 330. Inanother example, communication system 328 and user interface logic 330are items in the operator compartment 184 of sprayer 180, or in theoperator compartment of a towing vehicle (such as a tractor) that istowing planter 100. In any case, valve control system 113 may be able tointeract with a user interface 332 that can include user inputmechanisms 334, output mechanism 336, and it can include other items338.

FIG. 5 also shows that, in one example, valve control system 113 canreceive the row pressure sensor signals 340 generated by the rowpressure sensors 210 or 127. It can receive boom/supply line pressuresignal(s) 342 that is generated by boom pressure sensor 208 or supplyline pressure sensor 133 and, where multiple boom or supply linepressure sensors are used, it can receive signals 342 from each of them.It can receive boom/supply line flow signal(s) 343 generated by flowsensors (or flow meters) 131, 206 and, where a return line is used, itcan receive the flow signals from meters 135 and 207 as well. It is alsoshown receiving seed signal 123.

Before describing the valve control system 113, and its operation, inmore detail, a number of items in control system 113, and theiroperation will first be described.

Pressure sampling logic 302 illustratively samples the pressure signalsgenerated by row pressure sensors 210 and boom pressure sensor(s) 208.In one example, it samples the pressure at a frequency that is higherthan the frequency of the pulse width modulated signal that is used tocontrol valves 200. Thus, the pressure drop across the valves can besampled at the same frequency as well. In one example, the samplingfrequency is high enough so that the duty cycle of the pulse widthmodulated signal that is applied to each valve (or characteristic of theactual pulse of liquid through the valve—such as pulse duration, pulsefrequency, etc.) can be identified within a threshold amount of time.For example, it may be that the pressures (or the signals) are sampledat a rate which is multiple times that of the duty cycle of the pulsewidth modulated signal. In one example, the sampling rate is sufficientso that a pressure signal can be sampled twice during the active portionof the pulse width modulated signal. In another example, the samplingfrequency is sufficient so that the pressure signal can be sampled 4times, 8 times, or more, during the active portion of the duty cycle ofthe pulse width modulated signal. With a sufficient sampling rate, theduration of the pulse of liquid material through the corresponding valvecan be identified with a relatively high degree of accuracy, as can thebeginning and the end of the pulse of liquid. The higher the samplingfrequency, the higher the accuracy with which the characteristics of thepulse can be identified, and thus, the higher the accuracy with whichthe beginning and end of the pulse, the pulse frequency and pulseduration can be identified.

Row pressure identifying logic 306 illustratively receives the rowpressure signals 340 and generates a row pressure signal or valueindicative of the row pressure measured by the corresponding rowpressure sensor. This can be the pressure within the body of the valve204, or it can be pressure at the outlet end of the valve (or furtherdown stream toward the outlet end of the application assembly), so thatthe pressure drop across the valve can be identified. By way of example,if the valve is opened and the pressure at the outlet end of the valvemeasures at approximately atmospheric pressure (or at the same level ofthe other valves or at another expected level), then this will mean thatthe nozzle which is being fed by the valve is unclogged, and is allowingthe liquid material to pass through it and be dispersed on the field.Thus, the pressure drop across the valve will be indicative of the valueof the boom pressure indicated by the boom pressure sensor signal(s) 342less the pressure sensed by the row pressure sensor being processed.However, if the valve is open, but the row pressure sensor signalindicates that the measured row pressure is higher than the expectedpressure, this may mean that the corresponding nozzle is clogged, orpartially clogged. Thus, it will be appreciated that row pressureidentifying logic 306 can identify the actual pressure measured by therow pressure sensor being processed, or it can identify the pressuredrop across the valve corresponding to the row pressure sensor signal,or both. These and other architectures are contemplated herein.

Flow rate identifier logic 308 illustratively receives the boom/supplyline flow signal 340, indicative of the flow rate of liquid materialthrough the boom or supply line, that is generated by flow meter 206 orflow meter 131. Where no return line is used, then these flow signalsrepresent the total flow of liquid applied to the field. Where a returnline is used, then the return flow signal is also received from meter135 or 207 so the applied flow can be determined based on the differencebetween the flows measured by the meters. Row flow rate identifier logic308 divides the mass flow rate applied by the number of active valves ornozzles, to identify an average flow rate through each nozzle. Orificeidentifier logic 304 can then identify the average orifice size for eachnozzle based upon the pressure drop across the corresponding valve, andbased upon the average flow rate through the valve. This can be doneusing the following equation:

F _(V)=Valve C _(v)*√{square root over (P _(B)−P _(R))}

where F_(V) is the flow rate through a valve;

Valve C_(v) is a flow coefficient that represents the average orificesize of the valves;

P_(B) is the boom (or supply line) pressure indicated by one ofboom/supply line pressure signal(s) 342; and

P_(R) is the row pressure identified by row pressure signal 340.

Error/time delay correction logic 310 illustratively compares the pulsewidth modulated control signal that is controlling the valves to the rowpressure signal to identify a time delay between when the control signalcontrols the valve to open or close and when the row pressure signalindicates that the valve actually opened or closed.

There may be a time delay for a variety of different reasons. Forinstance, it may take more or less time to open or close the valve basedon general valve characteristics (such as spring strength), the currentdriver which drives the valve solenoid, the system pressure, the liquidcharacteristics, etc. These parameters can vary, and this can affectapplication accuracy, application rate, etc. Logic 310 can identifythese delays in near real time, during operation. It generates error ordelay signals indicative of the errors or delays and provides them toseed/chemical correlation logic 324. As is described in more detailbelow, seed location/pattern identifier 325 can identify seed locationor a pattern indicative of that location. Pulse frequency controller 327and pulse duration controller 329 can use that information, along withthe time delays, and can determine when the valves should be actuated,and for how long, to dispense the liquid material where desired. Basedon the signals from seed/chemical correlation logic 324, pulsed valvecontrol signal generator 312 controls the valves to dispense the liquidmaterial at the seed/plant location (e.g., for fertilizer), betweenseed/plant locations (e.g., for herbicide), or elsewhere.

Before describing that correlation is more detail, it should be notedthat error/delay correction logic 310 also illustratively compares theflow rate through a particular valve (based upon the pressure dropacross that valve and the calculated orifice size) and compares itagainst a target flow rate (which may be identified based on the boom orsupply line flow rate, or the applied flow rate, divided by the numberof nozzles on the system), the system average flow rate, or it maycompare the flow rate across a given nozzle to the flow rate acrossother nozzles on the sprayer or planter. Based upon the comparison,error correction logic 310 may identify errors introduced because ofspecific gravity considerations. It can then generate corrections forspecific gravity of the liquid, when the specific gravity of the liquidis obtained by error correction logic 310. In one example, an operatorcan use user input mechanism 334 to enter the specific gravity of theliquid. In another example, the identity of the liquid can be obtainedand the specific gravity of that liquid can be obtained from a remotesystem, from local memory (e.g., from data store 321), etc.

Pulse duration logic 314 illustratively identifies the beginning of thepulse of liquid, the end of the pulse of liquid and the duration of thepulse of liquid through the valve corresponding to each row, based uponthe sampled row pressure signals. This was described above. Pulsefrequency logic 316 illustratively identifies the frequency of the pulseof liquid through the valve, as also discussed above.

Valve blockage detector 320 illustratively identifies valve blockagesbased upon the various sensor signals. For instance, as discussed above,if the pressure drop across a particular valve is relatively small, evenwhen the valve is open, then this may indicate that that a nozzle isblocked, or partially blocked. The pressure drop across a valve may becompared to an expected pressure drop, to determine whether the nozzleis blocked, partially blocked, or whether the valve is broken, amongother things. In another example, instead of comparing to an expectedvalue, the pressure drop across the valve can be compared against thatof other valves. This overcomes effects related to things like varyingviscosity because, at any given time, the valves are all likely to besubject to similar conditions (which would affect things likeviscosity).

Flow volume detector 322 illustratively detects the volume of flowacross a particular valve for each activation of the valve. Forinstance, if the duration of the active portion of the pulse widthmodulated signal is identified by pulse duration logic 314, and the flowrate through the corresponding valve and nozzle combination isidentified by row flow rate identifier logic 308, then the volume ofliquid material dispensed for each valve actuation can be identified byflow volume detector 322.

In addition, logic 308 can identify the flow rate for all rows. They canbe aggregated over some time period and compared to the applied flowrate over that time period. Any difference can be used to adapt the flowrate calculation and therefore the pulse length commands as well. Thiscan be used to deal with viscosity and other similar unknowns.

Seed/chemical correlation logic 324 illustratively receives seed signal123 and the pulse start, pulse end, and pulse duration and pulsefrequency from logic 314 and 316, respectively, and generates a signalindicative of whether the liquid is to be dispensed at the seed/plantlocations or between those locations or elsewhere, and also indicativeof when the valve should be actuated, and for how long, to dispense theliquid at those locations. It can, for instance, correlated thedispersal of chemical through a particular nozzle, with the delivery ofa seed through a corresponding row unit. By way of example, if the rowunit illustrated FIG. 2 drops a seed, and the chemical being deliveredby the application assembly is a fertilizer chemical, then seed/chemicalcorrelation logic 324 correlates the timing between depositing a seed inthe furrow, and the application of chemical through the pulse widthmodulated operation of valve 109. In this way, chemical can be appliedin on a per-seed basis which enhances the efficient application ofchemical, where needed. Further, if the sprayer in FIGS. 3 and 4 is tospray a herbicide between the plant locations, then logic 324 correlatestiming between actuating the valves and the plant locations. Theoperation of seed/chemical correlation logic 324 is described in greaterdetail below with respect to FIG. 7.

Control signal generator logic 318 can illustratively generate othercontrol signals, based upon the various sensor signals and valuesgenerated. The control signals can be used to control any of a widevariety of different types of controllable subsystems, such as the speedof a sprayer or towing vehicle, the seed delivery system or seedmetering system, operator interface logic 330, or a wide variety ofother controllable subsystems. Also, valve control signal generator 312can control the actuation of valves 109, 200.

FIGS. 6A and 6B (herein after referred to as FIG. 6) show a flow diagramillustrating one example of the operation of valve control system 113 ingenerating control signals based upon the various sensor inputs. It isfirst assumed that a spraying system (or chemical application system)with a valve control system 113 is operating. This is indicated by block350 in the flow diagram of FIG. 6. In one example, the system isdeployed on a sprayer 180. In another example, it is deployed on aplanter row unit 106. Further, it is assumed that the valve controlsignal generator 312 is generating pulsed signals to control the variousvalves through which the liquid is being applied or sprayed. However,the valves may be controlled in other ways, where the control signalsare not pulsed, in which case some of the description below regardingpulsed valve control signals does not apply. The spraying system can beoperational in other ways as well, and this is indicated by 352.

Boom/supply line pressure identifier logic 305 then detects the boompressure from boom/supply line pressure signal(s) 342. The boom pressureis indicated by P_(B). Detecting the boom pressure P_(B) is indicated byblock 354 in the flow diagram of FIG. 6. In one example, it is sensedwith the boom pressure sensor 208 or supply line pressure sensor 131,which generates the sensor signal 342. It can also be sensed bydifferent boom pressure sensors located at different locations acrossboom 188 or supply line 111. This is indicated by block 356. The boompressure sensor can be generated by aggregating sensor values sensed bydifferent sensors. For instance, one or more of the row pressure sensorsignals can be aggregated to obtain the boom pressure value. This isindicated by block 358 in the flow diagram of FIG. 6. The boom pressurecan be sensed and identified in other ways as well. This is indicated byblock 360.

Boom/supply line flow rate identifier logic 307 then detects theapplication flow rate (e.g., the flow of liquid from tank 186 or 107into either boom 188 or supply line 111, respectively. This is indicatedby block 362 in the flow diagram of FIG. 6. This can be sensed using thecentral flow meter 206 or supply line flow meter 131. This is indicatedby block 364. In an example in which a return line is used, the flowthrough the return line can also be measured and subtracted from theflow into boom 188 or supply line 111. This is indicated by block 365.It can be sensed in other ways as well, such as aggregating the flowrate through the various valves or nozzles that the liquid material ispassing through. This is indicated by block 366.

Orifice identifier logic 304 then identifies a number of active valvesor nozzles in the system. This is indicated by block 368. In oneexample, this can be input by the operator using operator inputmechanisms 334. Determining the number of active valves or nozzles basedon an operator or user input is indicated by block 370 in the flowdiagram of FIG. 6. It can be done by detecting the number of activevalves or nozzles automatically. For instance, when the valves areturned on, the value of the row pressure sensed by row pressure sensors210 can be identified to determine whether fluid is passing through avalve and/or nozzle. In this way, the number of active valves or nozzlescan be identified automatically. Identifying the number of active valvesautomatically is indicated by block 372. The number of active valves canbe identified in other ways as well. This is indicated by block 374.

Orifice identifier logic 304 then generates a system orifice sizeindicator (C_(v)) for the spraying system. The system orifice sizeindicator C_(v) will illustratively be an aggregate of all the orificesof the active nozzles. Generating the system orifice size indicatorC_(v) is indicated by block 376 in the flow diagram of FIG. 6.

In one example, the system orifice indicator is based on the boompressure P_(B) and the application flow rate. The boom pressure P_(B) isillustratively indicated by the sensor signal from boom pressure sensor208. The application flow rate is illustratively indicated by the signalfrom flow meter 206 (and where a return line is used, based on the flowrate indicated by meter 207 as well). Generating C_(v) based on the boompressure and application flow rate is indicated by block 378 in the flowdiagram of FIG. 6. The same can be generated for planter 100 based onthe supply line pressure from sensor 132 and flow valve from flow meter131 (and possibly flow meter 135). It can be generated in other ways aswell. This is indicated by block 380.

Orifice identifier logic 304 then identifies a valve orifice sizeindicator (Valve C_(v)) which is indicative of the orifice size of thevalves (or the valve/nozzle combination) on the sprayer boom. Generatingthe valve orifice size indicator C_(v) is indicated by block 382 in theflow diagram of FIG. 6. In one example, Valve C_(v) is based upon thesystem C_(v) and the number of active valves. For instance, the systemC_(v) can be divided by the number of active valves to obtain a size foreach valve orifice. This is indicated by block 384. The Valve C_(v) canbe identified in other ways as well. This is indicated by block 386.

The row pressure identifying logic 306 detects a row pressure (P_(R))for each row. This is indicated by block 388. In one example, the rowpressure is sampled based upon a sampling frequency indicated bypressure sampling logic 302. The row pressure can be sampled at afrequency that is greater than the frequency of the pulsed valve controlsignal (e.g., the pulse width modulated valve control signal). This isindicated by block 390. The row pressures can be sampled by sampling therow pressure signals 340 from each of the row pressure sensors 210, 127.This is indicated by block 392. The row pressure, for each row, can bedetected in other ways as well. This is indicated by block 394.

Row flow rate identifier logic 308 then identifies a valve flow rate(F_(V)) for each row. The value F_(V) will identify the mass flow rateof an amount of liquid material passing through the valve when the valveis actuated by the pulse width modulated control signal. IdentifyingF_(V) for each row is indicated by block 396.

In one example, F_(V) can be identified based on P_(B), P_(R) and valveC_(v). For instance, the valve flow rate can be identified usingequation 1 above. This is indicated by block 396. The valve flow ratecan of course be identified in other ways as well, such as by placingindividual flow meters on the valves, or in other ways. This isindicated by block 400.

Pulse duration logic 314 then identifies the beginning of each pulse,the end of each pulse, and the pulse duration (or the time that thevalve is open). This is indicated by block 402. In one example, the rowpressure is monitored so that when the row pressure changes (indicatingthat the valve is open) this is monitored to identify when the pressureindicates that the valve is opened (the beginning of each pulse). Therow pressure is also monitored to identify when the pressure indicateswhen the valve is closed (the end of the pulse). The amount of timebetween when the valve opens and when it closes will identify theduration of the pulsed flow of liquid material through the valve forthat pulse. Thus, in one example, the row pressure is sampled at a highenough frequency that the beginning and end of the pulse and the pulseduration can be identified with a desired accuracy. The higher thesample frequency, the more accurately these pulse characteristics can beidentified. Identifying the pulse beginning and end and the pulseduration based on a detected variation of P_(R) is indicated by block404. The pulsed duration can be identified in other ways as well, andthis is indicated by block 406.

Pulse frequency logic 316 then identifies the pulse frequency. In oneexample, the pulse frequency is determined based upon the amount of timebetween transitions in the pulse width modulated signal from an inactivestate to an active state. The frequency with which the pulse widthmodulated signal makes this transition is illustratively a measure ofthe pulse frequency, itself. Identifying the pulse frequency isindicated by block 408.

As with the pulse duration, in one example, the pulse frequency can beidentified by detecting variations in the row pressure PR indicating thevalve opening and valve closing transitions. This is indicated by block410. The pulse frequency can be identified in other ways as well, andthis is indicated by block 412.

Valve blockage detector 320 then detects whether a given valve isblocked. This is indicated by 414. For instance, detector 320 canmonitor the row pressure signals 340 for each of the rows and identifywhether the row pressure is changing with the pulse width modulatedcontrol signal (or with ah non-pulsed control signal). By way ofexample, if the row pressure remains the same, regardless of whether thecorresponding valve is open or closed, this may indicate that the valveor nozzle is blocked or broken. Similarly, the amplitude of the pressurechange can be monitored as well. If the pressure change is only slight,depending on whether the valve is open or closed, this may indicate thatthe nozzle is partially blocked. Detecting a valve or nozzle blockagebased upon the row pressure P_(R) is indicated by block 416.

The valve or nozzle blockage can also be detected based upon the valveflow rate F_(V). If the flow rate through the valve is zero or less thanexpected, even when the valve is open this may indicate that the valveor nozzle is fully blocked or partially blocked. Detecting whether thevalve or nozzle is blocked based on F_(V) is indicated by block 418.

Detecting whether the valve or nozzle is blocked or partially blockedcan be done in other ways as well. This is indicated by block 420.

Flow volume detector 322 then detects the volume of liquid flow in thesystem. This is indicated by block 422. The flow volume can be detectedat a number of different levels. For instance, the volume of liquid flowat each row (through each valve or valve/nozzle combination) can beidentified. By way of example, it can be identified based upon the flowrate through each valve/nozzle combination, and the duty cycle of thecontrol signal (or the amount of time that the valve is actually open).Identifying the flow volume on a per row basis is indicated by block424.

In some cases, it may be that a single valve services multiple nozzles.In that case, the flow volume can be identified on a per-valve basis.This is indicated by block 426. The flow volume through a valve orvalve/nozzle combination can be identified over a given period of time(such as the volume of flow per minute), etc. This is indicated by block428. In another example, the flow volume can be identified for eachvalve actuation (e.g., the amount of liquid passing through the valvefor each valve actuation can be identified). This is indicated by block430. The flow volume can be detected in other ways as well. This isindicated by block 432.

Based upon all of the values that are detected and/or generated, controlsignal generator logic 318 and valve control signal generator 312 thenillustratively generate control signals to control the system. This isindicated by block 434.

Logic 312 can generate a wide variety of different types of controlsignals. For instance, it can use seed/chemical correlation logic 324 toperform valve control based upon seed or plant location, so that liquidmaterial is sprayed at the location of each seed or plant, between them,or relative to them in other ways, etc. This is indicated by block 436.It can perform valve control to apply a desired quantity when spotspraying. Since the flow volume is known on a per system and per nozzlebasis, then the valves can be controlled by valve control signalgenerator 312 to apply a desired volume at a desired location (such aswhen spot spraying for weeds or otherwise). The control can be performedbased on the time delay detected by logic 310 or in other ways as well.Performing valve control to apply a desired quantity when spot sprayingin indicated by block 438.

Control signal generator logic 312 can control the machine based uponblockage detection. For instance, when a blockage of a particular nozzleor valve is detected, then the control signal for that valve can bedisabled until the blockage is remedied. At the same time, controlsignal generator logic 318 can control user interface logic 330 to raisean alert for the operator. Similarly, logic 312 can control thefrequency of the pulse width modulated control signal in an attempt toclear the blockage. Control signals can be generated to control themachine based on blockage detection in other ways as well. This isindicated by block 440.

Control signal generator logic 318 can also generate a control signaland provide it to valve control signal generator 312 so that the pulsewidth modulated signals are generated to control the pulse frequency orduration. By way of example, assume that a sprayer is treating a certaintype of plant or weed, and the application of additional liquid volumemay be desired at a particular point in the field. The pulse frequencyor pulse duration of the pulse width modulated signal can be varied toadjust the volume of liquid material applied. This is indicated by block442.

In another example, the system may be meant to apply liquid to aspecific spot (e.g., close to the plant). The length of the spot towhich liquid is applied will be dependent on valve actuations anddriving speed. At relatively higher speed, the spot may be so long thatthe amount of liquid is not sufficiently concentrated. Thus, logic 318can generate a pump control signal to control the pump that pumps theliquid material to increase pressure at higher speeds and decreasepressure at lower speeds. Controlling the pump to adjust pressure basedon travel speed is indicated by block 441. In another example, logic 318generates speed control signals to control machine speed to attain thedesired concentration. These can also be done while controlling thevalves as well.

Control signal generator logic 318 can also generate a control signal tocontrol user interface logic 330 in various ways. This is indicated byblock 444. By way of example, when a blockage is detected, a userinterface output mechanism 336 can be controlled to surface thisinformation for the operator. Mechanism 336 may be a visual, audible orhaptic output device that is controlled to alert the operator to ablockage, or a set of blockages. The user interface logic can becontrolled in other way as well.

It will be appreciated that a wide variety of other control signals canbe generated. The control signals can be used to control subsystems of aplanter 100, of a towing vehicle, of a self propelled sprayer 180, or awide variety of other items. This is indicated by block 446.

FIG. 7 is a flow diagram illustrating one example of the operation ofseed/chemical correlation logic 324 in correlating the application of aliquid chemical with seed or plant location. Seed/chemical correlationlogic 324 first detects the seed/location indicating the location of aseed/plant. The seed/plant location can be detected in a variety ofdifferent ways. For instance, the number of seed signals 123 can bedetected for a threshold time period of time by seed location/patternidentifier 325. Identifier 325 can then detect a pattern indicative ofseed location. For example, it may identify that, based on the seedsignal 123, and the speed or location of the planter sensed by a speedsensor or location sensor (such as a GPS receiver), a seed is beingdropped every 6 inches, beginning at a location identified by the seedsignal 123. Once the pattern is identified, controllers 327 and 329 cancontrol valves 109, 204 to apply the liquid as desired, relative to theseeds or plants. They can control the pulse of liquid (its beginning andending, its frequency and duration) so it applies the liquid at theseed/plant locations, between those locations, elsewhere, etc.

In another example, identifier 325 identifies the seed/plant locationbased on the current seed signal 123. For instance, it can identify seedlocation by detecting seed presence at the seed sensor and determininghow long it will take for the seed to reach the ground. Based on thattime, logic 327 and 329 can control the timing, pulse frequency and/orduration, respectively to apply the liquid material as desired relativeto the seed.

Detecting the seed/plant location is indicated by block 450. Detectingthe location by identifying a pattern is indicated by block 451.Detecting the seed/plant location from a seed sensor signal 123 isindicated by block 452. The seed location can be identified in otherways as well. For instance, if a seed location map was generated whenseeds were planted, that map may be stored (e.g., remotely or in datastore 321) and may identify the geographical coordinates of theseed/plant locations. Thus, when a sprayer is traveling over thatportion of a field later, it can obtain the seed location map andidentify seed location based upon that map. When it travels over thefield, it can selectively apply the liquid material based on the seedlocations. Detecting seed location based upon a seed location map isindicated by block 454.

The seed location can be detected in other ways as well. This isindicated by block 456.

Seed/chemical correlation logic 324 then provides an output to valvecontrol signal generator 312 to generate a correlated, valve controlsignal, that is correlated to apply the liquid material based upon theseed/plant location. This is indicated by block 458. In doing so, timedelay correlation logic 310 identifies a time delay between when a valveis commanded to open or close and when it actually opens or closes basedon liquid pulse beginning and ending (as detected by pulse durationlogic 314) which is, itself, based on the variation in the sensed rowpressures. This is indicated by block 455 and it can be done for eachvalve that is being controlled. In addition, the time for the liquid toreach the field after passing through the nozzle can be sensed orestimated as well. Based on these delays, various parameters of theliquid pulse can be controlled to correlate the liquid delivery with theplant location to apply the liquid at a desired location relative to theplant location. The pulse frequency can be controlled by pulse frequencycontroller 327, as indicated by block 457. The pulse duration can becontrolled by pulse duration controller 329, as indicated by block 459.In one example, the control signal provided to pulsed valve controlsignal generator 312 controls generator 312 to generate the pulse widthmodulated signal in order to synchronize the application of the liquidsubstance to the seed/plant location. This is indicated by block 460. Inanother example, the control signals are also generated, and timed, toapply a desired amount of the liquid material per seed. This isindicated by block 462. By way of example, once the flow rate througheach nozzle or valve is known, timing and the duration of the pulsewidth modulated signal can be varied to apply a desired amount ofmaterial relative to a known seed/plant location. For instance, a smallamount of material may be applied on either side of the seed while arelatively large amount of the material is applied at the same locationof the seed. This is just one example. Also, the pulse width modulatedsignal can be generated to apply the liquid between (or to the side ofor otherwise offset from) the seed/plant locations. This is indicated byblock 461. Similarly, the machine speed and/or pump pressure (e.g., pumpdisplacement, etc.) can also be controlled to apply a desired amount ata desired spot. This is indicated by block 463. Generating a correlatedpulsed valve control signal, that is correlated to seed location, can beperformed in other ways as well. This is indicated by block 464.

FIG. 8 is a block diagram of an architecture in which machines aredisposed in a remote server (or cloud computing) architecture 500. Cloudcomputing provides computation, software, data access, and storageservices that do not require end-user knowledge of the physical locationor configuration of the system that delivers the services. In variousexamples, cloud computing delivers the services over a wide areanetwork, such as the internet, using appropriate protocols. Forinstance, cloud computing providers deliver applications over a widearea network and they can be accessed through a web browser or any othercomputing component. Software or components of architecture 500 as wellas the corresponding data, can be stored on servers at a remotelocation. The computing resources in a cloud computing environment canbe consolidated at a remote data center location or they can bedispersed. Cloud computing infrastructures can deliver services throughshared data centers, even though they appear as a single point of accessfor the user. Thus, the components and functions described herein can beprovided from a service provider at a remote location using a cloudcomputing architecture. Alternatively, they can be provided from aconventional server, or they can be installed on client devicesdirectly, or in other ways.

The description is intended to include both public cloud computing andprivate cloud computing. Cloud computing (both public and private)provides substantially seamless pooling of resources, as well as areduced need to manage and configure underlying hardware infrastructure.

A public cloud is managed by a vendor and typically supports multipleconsumers using the same infrastructure. Also, a public cloud, asopposed to a private cloud, can free up the end users from managing thehardware. A private cloud may be managed by the organization itself andthe infrastructure is typically not shared with other organizations. Theorganization still maintains the hardware to some extent, such asinstallations and repairs, etc.

In the example shown in FIG. 8, some items are similar to those shown inprevious Figures and they are similarly numbered. FIG. 8 specificallyshows that the machines 100, 180 can communicate (by using communicationsystem 428 in pulsing valve control system 113) with one or remotesystems 504 located in cloud 502 (which can be public, private, or acombination where portions are public while others are private).

FIG. 8 also depicts another example of a cloud architecture. FIG. 8shows that it is also contemplated that some components 430 of pulsingvalve control system 113 can be disposed in cloud 502 while others arenot. By way of example, data store 321 can be disposed outside of cloud502, and accessed through cloud 502. In one example, data store 321 caninclude historical data 470, one or more seed maps 472, liquidcharacteristics 474 (such as viscosity or specific gravitycharacteristics, etc.), desired application data 476 (such as desiredamounts, where to apply relative to plant location, etc.), and it caninclude other data 478. Regardless of where they are located, they canbe accessed directly by machines 100, 180, through a network (either awide area network or a local area network), they can be hosted at aremote site by a service, or they can be provided as a service through acloud or accessed by a connection service that resides in the cloud. Allof these architectures are contemplated herein.

It will also be noted that architecture 500, or portions of it, can bedisposed on a wide variety of different devices. Some of those devicesinclude servers, desktop computers, laptop computers, tablet computers,or other mobile devices, such as palm top computers, cell phones, smartphones, multimedia players, personal digital assistants, etc.

FIG. 9 is one example of a computing environment in which architecture100, or parts of it, (for example) can be deployed. With reference toFIG. 9, an example system for implementing some examples includes ageneral-purpose computing device in the form of a computer 810.Components of computer 810 may include, but are not limited to, aprocessing unit 820 (which can comprise processors or servers fromprevious FIGS.), a system memory 830, and a system bus 821 that couplesvarious system components including the system memory to the processingunit 820. The system bus 821 may be any of several types of busstructures including a memory bus or memory controller, a peripheralbus, and a local bus using any of a variety of bus architectures. By wayof example, and not limitation, such architectures include IndustryStandard Architecture (ISA) bus, Micro Channel Architecture (MCA) bus,Enhanced ISA (EISA) bus, Video Electronics Standards Association (VESA)local bus, and Peripheral Component Interconnect (PCI) bus also known asMezzanine bus. Memory and programs described with respect to FIG. 5 canbe deployed in corresponding portions of FIG. 9.

Computer 810 typically includes a variety of computer readable media.Computer readable media can be any available media that can be accessedby computer 810 and includes both volatile and nonvolatile media,removable and non-removable media. By way of example, and notlimitation, computer readable media may comprise computer storage mediaand communication media. Computer storage media is different from, anddoes not include, a modulated data signal or carrier wave. It includeshardware storage media including both volatile and nonvolatile,removable and non-removable media implemented in any method ortechnology for storage of information such as computer readableinstructions, data structures, program modules or other data. Computerstorage media includes, but is not limited to, RAM, ROM, EEPROM, flashmemory or other memory technology, CD-ROM, digital versatile disks (DVD)or other optical disk storage, magnetic cassettes, magnetic tape,magnetic disk storage or other magnetic storage devices, or any othermedium which can be used to store the desired information and which canbe accessed by computer 810. Communication media typically embodiescomputer readable instructions, data structures, program modules orother data in a transport mechanism and includes any informationdelivery media. The term “modulated data signal” means a signal that hasone or more of its characteristics set or changed in such a manner as toencode information in the signal. By way of example, and not limitation,communication media includes wired media such as a wired network ordirect-wired connection, and wireless media such as acoustic, RF,infrared and other wireless media. Combinations of any of the aboveshould also be included within the scope of computer readable media.

The system memory 830 includes computer storage media in the form ofvolatile and/or nonvolatile memory such as read only memory (ROM) 831and random access memory (RAM) 832. A basic input/output system 833(BIOS), containing the basic routines that help to transfer informationbetween elements within computer 810, such as during start-up, istypically stored in ROM 831. RAM 832 typically contains data and/orprogram modules that are immediately accessible to and/or presentlybeing operated on by processing unit 820. By way of example, and notlimitation, FIG. 9 illustrates operating system 834, applicationprograms 835, other program modules 836, and program data 837.

The computer 810 may also include other removable/non-removablevolatile/nonvolatile computer storage media. By way of example only,FIG. 9 illustrates a hard disk drive 841 that reads from or writes tonon-removable, nonvolatile magnetic media, and an optical disk drive 855that reads from or writes to a removable, nonvolatile optical disk 856such as a CD ROM or other optical media. Other removable/non-removable,volatile/nonvolatile computer storage media that can be used in theexemplary operating environment include, but are not limited to,magnetic tape cassettes, flash memory cards, digital versatile disks,digital video tape, solid state RAM, solid state ROM, and the like. Thehard disk drive 841 is typically connected to the system bus 821 througha non-removable memory interface such as interface 840, and optical diskdrive 855 are typically connected to the system bus 821 by a removablememory interface, such as interface 850.

Alternatively, or in addition, the functionality described herein can beperformed, at least in part, by one or more hardware logic components.For example, and without limitation, illustrative types of hardwarelogic components that can be used include Field-programmable Gate Arrays(FPGAs), Application-specific Integrated Circuits (ASICs),Application-specific Standard Products (ASSPs), System-on-a-chip systems(SOCs), Complex Programmable Logic Devices (CPLDs), etc.

The drives and their associated computer storage media discussed aboveand illustrated in FIG. 9, provide storage of computer readableinstructions, data structures, program modules and other data for thecomputer 810. In FIG. 9, for example, hard disk drive 841 is illustratedas storing operating system 844, application programs 845, other programmodules 846, and program data 847. Note that these components can eitherbe the same as or different from operating system 834, applicationprograms 835, other program modules 836, and program data 837. Operatingsystem 844, application programs 845, other program modules 846, andprogram data 847 are given different numbers here to illustrate that, ata minimum, they are different copies.

A user may enter commands and information into the computer 810 throughinput devices such as a keyboard 862, a microphone 863, and a pointingdevice 861, such as a mouse, trackball or touch pad. Other input devices(not shown) may include a joystick, game pad, satellite dish, scanner,or the like. These and other input devices are often connected to theprocessing unit 820 through a user input interface 860 that is coupledto the system bus, but may be connected by other interface and busstructures, such as a parallel port, game port or a universal serial bus(USB). A visual display 891 or other type of display device is alsoconnected to the system bus 821 via an interface, such as a videointerface 890. In addition to the monitor, computers may also includeother peripheral output devices such as speakers 897 and printer 896,which may be connected through an output peripheral interface 895.

The computer 810 is operated in a networked environment using logicalconnections to one or more remote computers, such as a remote computer880. The remote computer 880 may be a personal computer, a hand-helddevice, a server, a router, a network PC, a peer device or other commonnetwork node, and typically includes many or all of the elementsdescribed above relative to the computer 810. The logical connectionsdepicted in FIG. 9 include a local area network (LAN) 871 and a widearea network (WAN) 873, but may also include other networks such as acontroller area network (CAN) or others. Such networking environmentsare commonplace in offices, enterprise-wide computer networks, intranetsand the Internet.

When used in a LAN networking environment, the computer 810 is connectedto the LAN 871 through a network interface or adapter 870. When used ina WAN networking environment, the computer 810 typically includes amodem 872 or other means for establishing communications over the WAN873, such as the Internet. The modem 872, which may be internal orexternal, may be connected to the system bus 821 via the user inputinterface 860, or other appropriate mechanism. In a networkedenvironment, program modules depicted relative to the computer 810, orportions thereof, may be stored in the remote memory storage device. Byway of example, and not limitation, FIG. 9 illustrates remoteapplication programs 885 as residing on remote computer 880. It will beappreciated that the network connections shown are exemplary and othermeans of establishing a communications link between the computers may beused. It should also be noted that the different embodiments describedherein can be combined in different ways. That is, parts of one or moreembodiments can be combined with parts of one or more other embodiments.All of this is contemplated herein.

Example 1 is an agricultural machine, comprising:

a liquid reservoir that stores liquid to be applied to a field overwhich the agricultural machine is traveling;

a supply line that defines a supply conduit;

a plurality of valves disposed along the supply line, each valve havingan inlet end and an outlet end and being controlled to move between anopen position and a closed position by a valve control signal;

a pump system that pumps the liquid from the liquid reservoir along thesupply line to the inlet ends of the valves;

a plurality of nozzles, at least one nozzle corresponding to each valveso that when the corresponding valve is open, the liquid flows throughthe valve to the corresponding nozzle;

a plurality of row pressure sensors each sensing pressure at the outletend of one of the plurality of valves and generating a corresponding rowpressure signal indicative of the sensed pressure;

a system flowmeter configured to identify an applied flowrate of theliquid material out of the liquid reservoir and through the supplyconduit and generate an applied flowrate signal indicative of theapplied flowrate; and

a valve control signal generator that generates the valve control signalbased on the row pressure signals and the applied flowrate signal.

Example 2 is the agricultural machine of any or all previous examplesand further comprising:

orifice size identifier logic configured to receive an active valveindicator indicative of a number of active valves on the agriculturalmachine and to identify a valve orifice size based on the sensed appliedflowrate and the active valve indicator.

Example 3 is the agricultural machine of any or all previous examplesand further comprising:

valve row flowrate identifier logic configured to identify a valve rowflowrate for each valve based on the valve orifice size and the rowpressure signal from the corresponding row pressure sensor.

Example 4 is the agricultural machine of any or all previous examplesand further comprising:

a valve blockage detector configured to detect a valve blockage statefor a given valve based on the valve row flowrate for the given valve.

Example 5 is the agricultural machine of any or all previous exampleswherein the valve blockage detector is configured to compare the valverow flow rate for the given valve to at least one other valve row flowrate for a different valve to identify the blockage state.

Example 6 is the agricultural machine of any or all previous exampleswherein the blockage detector is configured to identify the blockagestate as at least one of blocked, unblocked and partially blocked basedon the comparison with the at least one other valve row flow rate.

Example 7 is the agricultural machine of any or all previous examplesand further comprising:

a supply line pressure sensor configured to sense pressure in the supplyline and generate a supply line pressure signal indicative of the sensedpressure in the supply line.

Example 8 is the agricultural machine of any or all previous examplesand further comprising:

row pressure identifying logic configured to identify a pressure dropacross a given nozzle based on the row pressure signal and the supplyline pressure signal.

Example 9 is the agricultural machine of any or all previous exampleswherein the supply line pressure sensor comprises:

a plurality of different supply line pressure sensors located to sensepressure at different locations along the supply line and to generate acorresponding different supply line pressure signal.

Example 10 is the agricultural machine of any or all previous exampleswherein the row pressure identifying logic is configured to identify thepressure drop across the given nozzle by comparing the row pressuresignal from the corresponding row pressure sensor to a given one of thedifferent supply line pressure signals generated by a given one of thesupply line pressure sensors located closest to the given row pressuresensor.

Example 11 is the agricultural machine of any or all previous examplesand further comprising a return line that returns liquid from the supplyline to the liquid reservoir, and wherein the system flow metercomprises:

a first flowmeter configured to identify a first flowrate of the liquidmaterial out of the liquid reservoir and through the supply conduit andgenerate a first flowrate signal indicative of the first flowrate; and

a second flow meter configured to identify a second flow rate of liquidmaterial through the return line into the liquid reservoir and togenerate a second flow rate signal indicative of the sensed secondflowrate.

Example 12 is the agricultural machine of any or all previous examplesand further comprising:

flow rate logic configured to identify the applied flow rate based on adifference between the first and second flow rate signals.

Example 13 is a method of controlling an agricultural machine,comprising:

pumping liquid from a liquid reservoir along a supply conduit, definedby a supply line, to an inlet end of each of a plurality of valvesdisposed along the supply line, each of the plurality of valves havingan outlet end and being controlled to move between an open position anda closed position by a valve control signal;

sensing pressure at the outlet end of each of the plurality of valves;

generating a row pressure signal corresponding to each valve and beingindicative of the sensed pressure at the outlet end of the correspondingvalve;

sensing an applied flowrate of the liquid material out of the liquidreservoir and through the supply conduit;

generating an applied flowrate signal indicative of the appliedflowrate; and

generating the valve control signal based on the row pressure signalsand the applied flowrate signal.

Example 14 is the method of any or all previous examples, and furthercomprising:

receiving an active valve indicator indicative of a number of activevalves on the agricultural machine;

identifying a valve orifice size based on the sensed applied flowrateand the active valve indicator; and

identifying a valve row flowrate for each valve based on the valveorifice size and the row pressure signal corresponding to the valve.

Example 15 is the method of any or all previous examples and furthercomprising:

detecting a valve blockage state for a given valve based on the valverow flowrate for the given valve.

Example 16 is the method of any or all previous examples whereindetecting a valve blockage state comprises:

comparing the valve row flow rate for the given valve to at least oneother valve row flow rate for a different valve to identify the blockagestate.

Example 17 is the method of any or all previous examples and furthercomprising:

-   -   sensing pressure in the supply line;

generating a supply line pressure signal indicative of the sensedpressure in the supply line; and

identifying, as the row pressure, a pressure drop across a given valvebased on the row pressure signal and the supply line pressure signal.

Example 18 is the method of any or all previous examples wherein sensingthe supply line pressure comprises sensing pressure at differentlocations along the supply line and generating a corresponding differentsupply line pressure signal and wherein identifying, as the rowpressure, a pressure drop across a given valve comprises:

comparing the row pressure signal corresponding to the given valve to agiven one of the different supply line pressure signals generated bysensing the supply line pressure at a location closest to the givenvalve.

Example 19 is the method of any or all previous examples wherein theagricultural machine includes a return line that returns liquid from thesupply line to the liquid reservoir, and wherein sensing an applied flowrate comprises:

sensing a first flowrate of the liquid material out of the liquidreservoir and through the supply conduit;

generating a first flowrate signal indicative of the first flowrate;

sensing a second flow rate of liquid material through the return lineinto the liquid reservoir;

generating a second flow rate signal indicative of the sensed secondflowrate; and

identifying the applied flow rate based on a difference between thefirst and second flow rate signals.

Example 20 is an agricultural machine, comprising:

a liquid reservoir that stores liquid to be applied to a field overwhich the agricultural machine is traveling;

a supply line that defines a supply conduit;

a plurality of valves disposed along the supply line, each valve havingan inlet end and an outlet end and being controlled to move between anopen position and a closed position by a valve control signal;

a pump system that pumps the liquid from the liquid reservoir along thesupply line to the inlet ends of the valves;

a plurality of nozzles, at least one nozzle corresponding to each valveso that when the corresponding valve is open, the liquid flows throughthe valve to the corresponding nozzle;

a plurality of row pressure sensors each sensing pressure at the outletend of one of the plurality of valves and generating a corresponding rowpressure signal indicative of the sensed pressure;

a system flowmeter configured to identify a system flowrate of theliquid material out of the liquid reservoir and through the supplyconduit and generate a system flowrate signal indicative of the systemflowrate;

orifice size identifier logic configured to receive an active valveindicator indicative of a number of active valves on the agriculturalmachine and to identify a valve orifice size based on the sensed systemflowrate and the active valve indicator;

valve row flowrate identifier logic configured to identify a valve rowflowrate for each valve based on the valve orifice size and the rowpressure signal from the corresponding row pressure sensor; and

a valve blockage detector configured to detect a blockage state of eachof the plurality of nozzles based on the valve flowrate for each of thecorresponding valves.

Although the subject matter has been described in language specific tostructural features and/or methodological acts, it is to be understoodthat the subject matter defined in the appended claims is notnecessarily limited to the specific features or acts described above.Rather, the specific features and acts described above are disclosed asexample forms of implementing the claims.

What is claimed is:
 1. An agricultural machine, comprising: a liquidreservoir that stores liquid to be applied to a field over which theagricultural machine is traveling; a supply line that defines a supplyconduit; a plurality of valves disposed along the supply line, eachvalve having an inlet end and an outlet end and being controlled to movebetween an open position and a closed position by a valve controlsignal; a pump system that pumps the liquid from the liquid reservoiralong the supply line to the inlet ends of the valves; a plurality ofnozzles, at least one nozzle corresponding to each valve so that whenthe corresponding valve is open, the liquid flows through the valve tothe corresponding nozzle; a plurality of row pressure sensors eachsensing pressure at the outlet end of one of the plurality of valves andgenerating a corresponding row pressure signal indicative of the sensedpressure; a system flowmeter configured to identify an applied flowrateof the liquid material out of the liquid reservoir and through thesupply conduit and generate an applied flowrate signal indicative of theapplied flowrate; and a valve control signal generator that generatesthe valve control signal based on the row pressure signals and theapplied flowrate signal.
 2. The agricultural machine of claim 1 andfurther comprising: orifice size identifier logic configured to receivean active valve indicator indicative of a number of active valves on theagricultural machine and to identify a valve orifice size based on thesensed applied flowrate and the active valve indicator.
 3. Theagricultural machine of claim 2 and further comprising: valve rowflowrate identifier logic configured to identify a valve row flowratefor each valve based on the valve orifice size and the row pressuresignal from the corresponding row pressure sensor.
 4. The agriculturalmachine of claim 3 and further comprising: a valve blockage detectorconfigured to detect a valve blockage state for a given valve based onthe valve row flowrate for the given valve.
 5. The agricultural machineof claim 4 wherein the valve blockage detector is configured to comparethe valve row flow rate for the given valve to at least one other valverow flow rate for a different valve to identify the blockage state. 6.The agricultural machine of claim 5 wherein the blockage detector isconfigured to identify the blockage state as at least one of blocked,unblocked and partially blocked based on the comparison with the atleast one other valve row flow rate.
 7. The agricultural machine ofclaim 4 and further comprising: a supply line pressure sensor configuredto sense pressure in the supply line and generate a supply line pressuresignal indicative of the sensed pressure in the supply line.
 8. Theagricultural machine of claim 7 and further comprising: row pressureidentifying logic configured to identify a pressure drop across a givennozzle based on the row pressure signal and the supply line pressuresignal.
 9. The agricultural machine of claim 8 wherein the supply linepressure sensor comprises: a plurality of different supply line pressuresensors located to sense pressure at different locations along thesupply line and to generate a corresponding different supply linepressure signal.
 10. The agricultural machine of claim 9 wherein the rowpressure identifying logic is configured to identify the pressure dropacross the given nozzle by comparing the row pressure signal from thecorresponding row pressure sensor to a given one of the different supplyline pressure signals generated by a given one of the supply linepressure sensors located closest to the given row pressure sensor. 11.The agricultural machine of claim 1 and further comprising a return linethat returns liquid from the supply line to the liquid reservoir, andwherein the system flow meter comprises: a first flowmeter configured toidentify a first flowrate of the liquid material out of the liquidreservoir and through the supply conduit and generate a first flowratesignal indicative of the first flowrate; and a second flow meterconfigured to identify a second flow rate of liquid material through thereturn line into the liquid reservoir and to generate a second flow ratesignal indicative of the sensed second flowrate.
 12. The agriculturalmachine of claim 11 and further comprising: flow rate logic configuredto identify the applied flow rate based on a difference between thefirst and second flow rate signals.
 13. A method of controlling anagricultural machine, comprising: pumping liquid from a liquid reservoiralong a supply conduit, defined by a supply line, to an inlet end ofeach of a plurality of valves disposed along the supply line, each ofthe plurality of valves having an outlet end and being controlled tomove between an open position and a closed position by a valve controlsignal; sensing pressure at the outlet end of each of the plurality ofvalves; generating a row pressure signal corresponding to each valve andbeing indicative of the sensed pressure at the outlet end of thecorresponding valve; sensing an applied flowrate of the liquid materialout of the liquid reservoir and through the supply conduit; generatingan applied flowrate signal indicative of the applied flowrate; andgenerating the valve control signal based on the row pressure signalsand the applied flowrate signal.
 14. The method of claim 13, and furthercomprising: receiving an active valve indicator indicative of a numberof active valves on the agricultural machine; identifying a valveorifice size based on the sensed applied flowrate and the active valveindicator; and identifying a valve row flowrate for each valve based onthe valve orifice size and the row pressure signal corresponding to thevalve.
 15. The method of claim 14 and further comprising: detecting avalve blockage state for a given valve based on the valve row flowratefor the given valve.
 16. The method of claim 15 wherein detecting avalve blockage state comprises: comparing the valve row flow rate forthe given valve to at least one other valve row flow rate for adifferent valve to identify the blockage state.
 17. The method of claim15 and further comprising: sensing pressure in the supply line;generating a supply line pressure signal indicative of the sensedpressure in the supply line; and identifying, as the row pressure, apressure drop across a given valve based on the row pressure signal andthe supply line pressure signal.
 18. The method of claim 17 whereinsensing the supply line pressure comprises sensing pressure at differentlocations along the supply line and generating a corresponding differentsupply line pressure signal and wherein identifying, as the rowpressure, a pressure drop across a given valve comprises: comparing therow pressure signal corresponding to the given valve to a given one ofthe different supply line pressure signals generated by sensing thesupply line pressure at a location closest to the given valve.
 19. Themethod of claim 13 wherein the agricultural machine includes a returnline that returns liquid from the supply line to the liquid reservoir,and wherein sensing an applied flow rate comprises: sensing a firstflowrate of the liquid material out of the liquid reservoir and throughthe supply conduit; generating a first flowrate signal indicative of thefirst flowrate; sensing a second flow rate of liquid material throughthe return line into the liquid reservoir; generating a second flow ratesignal indicative of the sensed second flowrate; and identifying theapplied flow rate based on a difference between the first and secondflow rate signals.
 20. An agricultural machine, comprising: a liquidreservoir that stores liquid to be applied to a field over which theagricultural machine is traveling; a supply line that defines a supplyconduit; a plurality of valves disposed along the supply line, eachvalve having an inlet end and an outlet end and being controlled to movebetween an open position and a closed position by a valve controlsignal; a pump system that pumps the liquid from the liquid reservoiralong the supply line to the inlet ends of the valves; a plurality ofnozzles, at least one nozzle corresponding to each valve so that whenthe corresponding valve is open, the liquid flows through the valve tothe corresponding nozzle; a plurality of row pressure sensors eachsensing pressure at the outlet end of one of the plurality of valves andgenerating a corresponding row pressure signal indicative of the sensedpressure; a system flowmeter configured to identify a system flowrate ofthe liquid material out of the liquid reservoir and through the supplyconduit and generate a system flowrate signal indicative of the systemflowrate; orifice size identifier logic configured to receive an activevalve indicator indicative of a number of active valves on theagricultural machine and to identify a valve orifice size based on thesensed system flowrate and the active valve indicator; valve rowflowrate identifier logic configured to identify a valve row flowratefor each valve based on the valve orifice size and the row pressuresignal from the corresponding row pressure sensor; and a valve blockagedetector configured to detect a blockage state of each of the pluralityof nozzles based on the valve flowrate for each of the correspondingvalves.